9'1 Photosynthesis and Cellular Respiration

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9.1Photosynthesis and Cellular Respiration
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Intro What is Photosynthesis?

• The chemical reaction in plants that occurs when
  sunlight is captured and converted to chemical
  energy.
• The chemical energy is stored in an organic
  compound, glucose (a simple sugar).

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Photosynthesis Overview

• Def process by which plants, algae and some
  bacteria use sunlight, CO2 and H2O to produce
  sugar and oxygen.
• 1st step Capture radiant energy (from the sun)
  and convert it to chemical energy.
• 2nd step Use chemical energy to convert CO2 to
  glucose.
• Takes place in the chloroplasts, using
  chlorophyll, the green pigment in plants.

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EQUATION FOR PHOTOSYNTHESIS
WATER
OXYGEN
6CO2
6H2O
ENERGY
C6H12O6
6O2
CARBON DIOXIDE
GLUCOSE
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Plant pigments

• Pigments are materials that absorb particular
  wavelengths of light and reflect others
• Why do your eyes have a ___ color?
• Why do most plants have a green color?
• The pigment, chlorophyll,
• absorbs sunlight and
• energy is transferred to
• electrons which boosts
• them to a higher state.
  

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After sunlight is captured by chlorophyll, what
happens next?
The Calvin Cycle

• Chlorophyll temporarily stores the suns energy
  in the form of ATP and NADPH.
• This stored energy powers the Calvin cycle.
• The Calvin cycle uses CO2 and the ATP NADPH to
  store the suns energy long term.
• It is stored as the organic compound glucose.

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Review What happens during photosynthesis?

• Basically, plants capture the suns energy, and
  use that energy to make and store glucose.
• It occurs in the chloroplast, where the pigment
  chlorophyll, changes molecules of carbon dioxide
  and water into glucose.
• The Calvin Cycle is the final step.
• Oxygen is released in this reaction.
• Short term energy ATP
• Long term energy glucose

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Why is photosynthesis important to us?

• We cannot make our own food (glucose, energy),
  we must get our food from plants.
• Plants are the first step in the food chain.
• The oxygen released during photosynthesis is
  necessary for all living things.

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What factors affect photosynthesis?

• Light intensity
• More light more photosynthesis
• Upper limit occurs when all chlorophyll is being
  used.
• CO2 concentration
• More CO2 more photosynthesis
• Same reason as above.
• Temperature
• Requires a certain temp range
• Enzymes are used to speed up reactions, enzymes
  require a certain temp to work correctly.
• Turn to pg. 205 in your book!

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Moving Along

• Lets look at Cellular Respiration

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Intro What is Cellular Respiration?

• Organisms extracting the energy stored in
  glucose.
• Recall that in photosynthesis, the suns energy
  is converted into chemical energy (sugar) for
  long term storage.
• Organisms must remove the sugar from storage and
  then transform it into a form that can be used by
  the organism.

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Cellular Respiration Overview

• Def Process by which cells produce energy, in
  the form of ATP, from carbohydrates (sugars
  specifically glucose), in the presence of oxygen.
• Why do we breathe (external respiration)?
• Why do we consume and digest
  
  carbohydrates?
• Happens in more than one step.

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EQUATION FOR RESPIRATION
CARBON DIOXIDE
ATP
GLUCOSE
C6H12O6
6O2
6CO2
6H2O
ENERGY
OXYGEN
WATER
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Why does cellular respiration convert glucose to
ATP?

• Glucose long term stored energy.
• ATP temporary form of energy that can be
  quickly used for cellular activity.

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Recall What is ATP?

• ATP adenosine triphosphate
• Molecule that is the main energy source for all
  living things.
• Energy is released when the last phosphate group
  is removed.

Three Phosphate Groups
Base (adenine)
Energy
Sugar (ribose)
Removed to Make
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Review What is Cellular Respiration?

• The breakdown of glucose molecules to release
  energy in the form of ATP.
• Takes place in all living things.
• Oxygen gas in required!

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1st Step Glycolysis

• Series of chemical reactions that break down one
  molecule of glucose to form ATP.
• Produces 2 ATP molecules.
• Happens in cytoplasm of the cell
• May be anaerobic (happens without oxygen) or
  aerobic (happens with oxygen).
• Anaerobic ? fermentation
• Aerobic ? just the first step of cellular resp

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2nd Step Krebs cycle (Aerobic)

• Series of reactions that finishes glucose break
  down to carbon dioxide in the presence of oxygen.
• Happens in the mitochondria.
• 1 ATP produced

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3rd Step Electron Transport Chain

• Process that uses high energy electrons from
  Krebs cycle to convert molecules to ATP.
• Happens on the inner membranes of the
  mitochondria
• Up to 34 ATP produced

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Overview of photosynthesis and respiration
SUN
RADIANT ENERGY
CELL ACTIVITIES
PHOTOSYNTHESIS
RESPIRATION
GLUCOSE
ATP(ENERGY)
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Fill out the following chart to compare
Photosynthesis and Cellular Respiration
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Photosynthesis Cellular Respiration comparison
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Food Chain andEnergy Flow
Primary Producer Plant/ algae Primary
consumer Herbivores Secondary consumer Primary
Carnivore Tertiary consumer Top Carnivore
Autotroph (producer) Gets energy from the
Sun ? Does photosynthesis Cellular
Resp. Heterotroph (consumer) Gets energy from
Food ? Does cellular respiration
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Food Chain Example